Applicators of this type are also referred to as wire core applicators.
These applicators are still greatly appreciated today, because not only do they afford advantages with regard to their application, but also have various advantages in production that cannot be achieved with the injected applicators that compete with them. For example, small series can also be manufactured rather effectively because as a rule, very different wire core applicators can be produced on the existing production systems without considerable sums having to be invested in new tools for the one special applicator, unlike for injected applicators.
In general, it also applies to wire core applicators that they are supposed to meet two requirements, in particular:
Their bristle covering is supposed to have as great a mass storage capacity as possible so that the applicator needs to be dipped into the cosmetics supply only once or only a few times in order to envelop the eyelashes with a sufficiently voluminous layer of mascara mass.
On the other hand, their bristle covering is supposed to have as good a separation capacity as possible, i.e. the capacity of separating obliquely overlying eyelashes of the curve of the eyelashes and aligning them in a largely parallel manner. The reason for this is not least that the eyelashes can only be provided with the desired volume by means of the mascara mass if they are each coated all around individually, and not already previously drenched and stuck together in clumps with mascara mass.
In general, it thus applies to wire core applicators that they are supposed to meet high requirements, in particular, for the mass storage capacity with regard to the substance that is to be applied with them.
In the present case, however, the point is not only to increase the mass storage capacity to such an extent that the applicator does not have to be dipped in anew and recharged all too often during the application of mascara. The primary additional point is to ensure also that an eyelash is wetted as intensively as possible with mascara mass during an application process in order to instantly make the eyelashes appear as voluminous as possible in this manner—without having to coat the eyelashes several times and, in the process, take the risk that the separating action suffers and that adjacent eyelashes still stick together at some point due to the multiple application of mascara.
The approach to achieve this is to provide the mascara applicator with bristles that, each for itself, carries as thick a film of mascara mass as possible after dipping them into the mascara supply.
The U.S. Pat. No. 6,311,359 has already proposed in the prior art how to produce bristles for paintbrushes for painting walls and ceilings that, each for itself, is able to carry as thick a paint film as possible. For this purpose, particles (of a most frequently inorganic nature) that roughen the surface of the filaments used later as bristles considerably, because the particles protrude in each case over the surface directly surrounding them, are added to the plastic material prior to extruding the thread or the fiber from which the filaments are cut that later form the bristles.
Instead of for paintbrushes, such bristles can also be used in mascara applicators. However, the practical implementation shows that these particular bristles that provide the respective brush with a superior application behavior when used in paintbrushes do not provide any major improvements when incorporated into mascara applicators.
The reason for this may be found in the different covering density, and may primarily be that the mechanism causing the discharge of the paint is a totally different one in a paintbrush to that in a mascara applicator. A paintbrush is pressed against the surface to be coated with the paint with some force, which triggers the discharge of the generally rather highly liquid paint that adheres to the bristles.
This is different in a mascara applicator. Here, the bristles are not pressed against the eyelashes while exerting a force; rather, the eyelashes slide into the interspaces between the bristles and only touch the bristles.
Therefore, it is clear why it is possible that the bristles, which are roughened by admixing the particles and are therefore provided with a better mass storage capacity, are unable to provide the superior effect when used in a mascara applicator that they are able to provide in paintbrushes.
In order to improve the combing result of a mascara brush, and thus the application of mascara, DE 102 32 589 A1 proposed to configure the bristle tips in a tapering manner with a wedge-shaped cross section.